A new three carbon homologation via sulfur containing heterocyclic systems

A new reagent, based on a 5,6-dihydro-1,4-dithiin heterocyclic system1, has been devised and conveniently used for 3 carbon elongations of various electrophiles. In fact, it acts as either a propenyl alcohol or an acrolein anion equivalent, introducing into the new molecule a moiety consisting of fully protected double bond and allylic oxygen.